Areas of Seal R/D at GE

About four years ago, work was completed on a 36 inch diameter gas to gas carbon ring seal used to buffer low pressure turbine air at the rim of the forward outer flowpath on the GE36 unducted fan (UDF) engine. At about the same time, we were developing a long life counter-rotating intershaft air-oil seal of approximately 7.6 inch diameter for operation at 800 fps, 800 F, and 50 psid. Although we were successful in meeting most program goals with a split ring seal of the axial bushing type, the seal with the greatest payoff in life and air leakage rates, bearing many features in common with the GE36 seal, could not be successfully tested because of the structural weakness of the primary seal ring carbon material. This was a split ring seal using a hybrid combination of orifice compensated hydrostatic and shrouded hydrodynamic gas bearings. We are presently working to develop this design in conjunction with high strength materials being developed by Pure Carbon Co. In the area of engine secondary gas flow path-sealing for performance improvement, we are currently working with carbon and all metal face seals. A 15 inch diameter all metal 'aspirating' face seal, using self-acting hydrostatic bearings, was successfully tested to 700 fps, 100 psid, and 1000 F, demonstrating long life at flow reduction of 86 percent compared to a 'best' labyrinth. This seal will be developed through 1400 F, 900 fps, and 350 psid. The seal 'aspirates' closed at about idle speed pressure during engine start and reopens at engine shutdown. A hydraulic thrust balance seal, currently using orifice compensated hydrostatics, is under development. Other aspects of these projects are briefly covered

Micro-organism distribution sampling for bioassays

Purpose of sampling distribution is to characterize sample-to-sample variation so statistical tests may be applied, to estimate error due to sampling (confidence limits) and to evaluate observed differences between samples. Distribution could be used for bioassays taken in hospitals, breweries, food-processing plants, and pharmaceutical plants

Quantum geometry from 2+1 AdS quantum gravity on the torus

Wilson observables for 2+1 quantum gravity with negative cosmological constant, when the spatial manifold is a torus, exhibit several novel features: signed area phases relate the observables assigned to homotopic loops, and their commutators describe loop intersections, with properties that are not yet fully understood. We describe progress in our study of this bracket, which can be interpreted as a q-deformed Goldman bracket, and provide a geometrical interpretation in terms of a quantum version of Pick's formula for the area of a polygon with integer vertices.Comment: 19 pages, 11 figures, revised with more explanations, improved figures and extra figures. To appear GER

09-03 "Economic Writing on the Pressing Problems of the Day: The Roles of Moral Intuition and Methodological Confusion"

Economists are often called on to help address pressing problems of the day, yet many economists are uncomfortable about disclosing the values that they bring to this work. This essay explores how an inadequate understanding of the role of methodology, as related to ethics and human emotions of concern, underlies this reluctance and compromises the quality of economic advice. The tension between caring about the problems, on the one hand, and writing within the existing culture of the discipline, on the other, are illustrated with examples from U.S. policymaking, behavioral economics, and the economics of climate change and global poverty. Potential steps towards a more responsible, "strongly objective," and policy-useful economics are discussed.

09-07 "Getting Past "Rational Man/Emotional Woman": How Far Have Research Programs in Happiness and Interpersonal Relations Progressed?"

Orthodox neoclassical economics portrays reason as far more important than emotion, autonomy as more characteristic of economic life than social connection, and, more generally, things culturally and cognitively associated with masculinity as more central than things associated with femininity. Research from contemporary neuroscience suggests that such biases are related to certain automatic processes in the brain, and feminist scholarship suggests ways of getting beyond them. The "happiness" and "interpersonal relations" research programs have made substantial progress in overcoming a number these biases. Analysis from a feminist economics perspective suggests, however, several fronts on which research could most profitably continue.